1/* 2 * net/sched/cls_api.c Packet classifier API. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 * 11 * Changes: 12 * 13 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support 14 * 15 */ 16 17#include <asm/uaccess.h> 18#include <asm/system.h> 19#include <linux/bitops.h> 20#include <linux/module.h> 21#include <linux/types.h> 22#include <linux/kernel.h> 23#include <linux/string.h> 24#include <linux/mm.h> 25#include <linux/socket.h> 26#include <linux/sockios.h> 27#include <linux/in.h> 28#include <linux/errno.h> 29#include <linux/interrupt.h> 30#include <linux/netdevice.h> 31#include <linux/skbuff.h> 32#include <linux/init.h> 33#include <linux/kmod.h> 34#include <linux/netlink.h> 35#include <net/netlink.h> 36#include <net/sock.h> 37#include <net/pkt_sched.h> 38#include <net/pkt_cls.h> 39 40#define DPRINTK(format,args...) 41 42/* The list of all installed classifier types */ 43 44static struct tcf_proto_ops *tcf_proto_base; 45 46/* Protects list of registered TC modules. It is pure SMP lock. */ 47static DEFINE_RWLOCK(cls_mod_lock); 48 49/* Find classifier type by string name */ 50 51static struct tcf_proto_ops * tcf_proto_lookup_ops(struct rtattr *kind) 52{ 53 struct tcf_proto_ops *t = NULL; 54 55 if (kind) { 56 read_lock(&cls_mod_lock); 57 for (t = tcf_proto_base; t; t = t->next) { 58 if (rtattr_strcmp(kind, t->kind) == 0) { 59 if (!try_module_get(t->owner)) 60 t = NULL; 61 break; 62 } 63 } 64 read_unlock(&cls_mod_lock); 65 } 66 return t; 67} 68 69/* Register(unregister) new classifier type */ 70 71int register_tcf_proto_ops(struct tcf_proto_ops *ops) 72{ 73 struct tcf_proto_ops *t, **tp; 74 int rc = -EEXIST; 75 76 write_lock(&cls_mod_lock); 77 for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next) 78 if (!strcmp(ops->kind, t->kind)) 79 goto out; 80 81 ops->next = NULL; 82 *tp = ops; 83 rc = 0; 84out: 85 write_unlock(&cls_mod_lock); 86 return rc; 87} 88 89int unregister_tcf_proto_ops(struct tcf_proto_ops *ops) 90{ 91 struct tcf_proto_ops *t, **tp; 92 int rc = -ENOENT; 93 94 write_lock(&cls_mod_lock); 95 for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next) 96 if (t == ops) 97 break; 98 99 if (!t) 100 goto out; 101 *tp = t->next; 102 rc = 0; 103out: 104 write_unlock(&cls_mod_lock); 105 return rc; 106} 107 108static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n, 109 struct tcf_proto *tp, unsigned long fh, int event); 110 111 112/* Select new prio value from the range, managed by kernel. */ 113 114static __inline__ u32 tcf_auto_prio(struct tcf_proto *tp) 115{ 116 u32 first = TC_H_MAKE(0xC0000000U,0U); 117 118 if (tp) 119 first = tp->prio-1; 120 121 return first; 122} 123 124/* Add/change/delete/get a filter node */ 125 126static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg) 127{ 128 struct rtattr **tca; 129 struct tcmsg *t; 130 u32 protocol; 131 u32 prio; 132 u32 nprio; 133 u32 parent; 134 struct net_device *dev; 135 struct Qdisc *q; 136 struct tcf_proto **back, **chain; 137 struct tcf_proto *tp; 138 struct tcf_proto_ops *tp_ops; 139 struct Qdisc_class_ops *cops; 140 unsigned long cl; 141 unsigned long fh; 142 int err; 143 144replay: 145 tca = arg; 146 t = NLMSG_DATA(n); 147 protocol = TC_H_MIN(t->tcm_info); 148 prio = TC_H_MAJ(t->tcm_info); 149 nprio = prio; 150 parent = t->tcm_parent; 151 cl = 0; 152 153 if (prio == 0) { 154 /* If no priority is given, user wants we allocated it. */ 155 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE)) 156 return -ENOENT; 157 prio = TC_H_MAKE(0x80000000U,0U); 158 } 159 160 /* Find head of filter chain. */ 161 162 /* Find link */ 163 if ((dev = __dev_get_by_index(t->tcm_ifindex)) == NULL) 164 return -ENODEV; 165 166 /* Find qdisc */ 167 if (!parent) { 168 q = dev->qdisc_sleeping; 169 parent = q->handle; 170 } else if ((q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent))) == NULL) 171 return -EINVAL; 172 173 /* Is it classful? */ 174 if ((cops = q->ops->cl_ops) == NULL) 175 return -EINVAL; 176 177 /* Do we search for filter, attached to class? */ 178 if (TC_H_MIN(parent)) { 179 cl = cops->get(q, parent); 180 if (cl == 0) 181 return -ENOENT; 182 } 183 184 /* And the last stroke */ 185 chain = cops->tcf_chain(q, cl); 186 err = -EINVAL; 187 if (chain == NULL) 188 goto errout; 189 190 /* Check the chain for existence of proto-tcf with this priority */ 191 for (back = chain; (tp=*back) != NULL; back = &tp->next) { 192 if (tp->prio >= prio) { 193 if (tp->prio == prio) { 194 if (!nprio || (tp->protocol != protocol && protocol)) 195 goto errout; 196 } else 197 tp = NULL; 198 break; 199 } 200 } 201 202 if (tp == NULL) { 203 /* Proto-tcf does not exist, create new one */ 204 205 if (tca[TCA_KIND-1] == NULL || !protocol) 206 goto errout; 207 208 err = -ENOENT; 209 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE)) 210 goto errout; 211 212 213 /* Create new proto tcf */ 214 215 err = -ENOBUFS; 216 if ((tp = kzalloc(sizeof(*tp), GFP_KERNEL)) == NULL) 217 goto errout; 218 err = -EINVAL; 219 tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND-1]); 220 if (tp_ops == NULL) { 221#ifdef CONFIG_KMOD 222 struct rtattr *kind = tca[TCA_KIND-1]; 223 char name[IFNAMSIZ]; 224 225 if (kind != NULL && 226 rtattr_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) { 227 rtnl_unlock(); 228 request_module("cls_%s", name); 229 rtnl_lock(); 230 tp_ops = tcf_proto_lookup_ops(kind); 231 /* We dropped the RTNL semaphore in order to 232 * perform the module load. So, even if we 233 * succeeded in loading the module we have to 234 * replay the request. We indicate this using 235 * -EAGAIN. 236 */ 237 if (tp_ops != NULL) { 238 module_put(tp_ops->owner); 239 err = -EAGAIN; 240 } 241 } 242#endif 243 kfree(tp); 244 goto errout; 245 } 246 tp->ops = tp_ops; 247 tp->protocol = protocol; 248 tp->prio = nprio ? : tcf_auto_prio(*back); 249 tp->q = q; 250 tp->classify = tp_ops->classify; 251 tp->classid = parent; 252 if ((err = tp_ops->init(tp)) != 0) { 253 module_put(tp_ops->owner); 254 kfree(tp); 255 goto errout; 256 } 257 258 qdisc_lock_tree(dev); 259 tp->next = *back; 260 *back = tp; 261 qdisc_unlock_tree(dev); 262 263 } else if (tca[TCA_KIND-1] && rtattr_strcmp(tca[TCA_KIND-1], tp->ops->kind)) 264 goto errout; 265 266 fh = tp->ops->get(tp, t->tcm_handle); 267 268 if (fh == 0) { 269 if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) { 270 qdisc_lock_tree(dev); 271 *back = tp->next; 272 qdisc_unlock_tree(dev); 273 274 tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER); 275 tcf_destroy(tp); 276 err = 0; 277 goto errout; 278 } 279 280 err = -ENOENT; 281 if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE)) 282 goto errout; 283 } else { 284 switch (n->nlmsg_type) { 285 case RTM_NEWTFILTER: 286 err = -EEXIST; 287 if (n->nlmsg_flags&NLM_F_EXCL) 288 goto errout; 289 break; 290 case RTM_DELTFILTER: 291 err = tp->ops->delete(tp, fh); 292 if (err == 0) 293 tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER); 294 goto errout; 295 case RTM_GETTFILTER: 296 err = tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER); 297 goto errout; 298 default: 299 err = -EINVAL; 300 goto errout; 301 } 302 } 303 304 err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh); 305 if (err == 0) 306 tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER); 307 308errout: 309 if (cl) 310 cops->put(q, cl); 311 if (err == -EAGAIN) 312 /* Replay the request. */ 313 goto replay; 314 return err; 315} 316 317static int 318tcf_fill_node(struct sk_buff *skb, struct tcf_proto *tp, unsigned long fh, 319 u32 pid, u32 seq, u16 flags, int event) 320{ 321 struct tcmsg *tcm; 322 struct nlmsghdr *nlh; 323 unsigned char *b = skb_tail_pointer(skb); 324 325 nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags); 326 tcm = NLMSG_DATA(nlh); 327 tcm->tcm_family = AF_UNSPEC; 328 tcm->tcm__pad1 = 0; 329 tcm->tcm__pad1 = 0; 330 tcm->tcm_ifindex = tp->q->dev->ifindex; 331 tcm->tcm_parent = tp->classid; 332 tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol); 333 RTA_PUT(skb, TCA_KIND, IFNAMSIZ, tp->ops->kind); 334 tcm->tcm_handle = fh; 335 if (RTM_DELTFILTER != event) { 336 tcm->tcm_handle = 0; 337 if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0) 338 goto rtattr_failure; 339 } 340 nlh->nlmsg_len = skb_tail_pointer(skb) - b; 341 return skb->len; 342 343nlmsg_failure: 344rtattr_failure: 345 nlmsg_trim(skb, b); 346 return -1; 347} 348 349static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n, 350 struct tcf_proto *tp, unsigned long fh, int event) 351{ 352 struct sk_buff *skb; 353 u32 pid = oskb ? NETLINK_CB(oskb).pid : 0; 354 355 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 356 if (!skb) 357 return -ENOBUFS; 358 359 if (tcf_fill_node(skb, tp, fh, pid, n->nlmsg_seq, 0, event) <= 0) { 360 kfree_skb(skb); 361 return -EINVAL; 362 } 363 364 return rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO); 365} 366 367struct tcf_dump_args 368{ 369 struct tcf_walker w; 370 struct sk_buff *skb; 371 struct netlink_callback *cb; 372}; 373 374static int tcf_node_dump(struct tcf_proto *tp, unsigned long n, struct tcf_walker *arg) 375{ 376 struct tcf_dump_args *a = (void*)arg; 377 378 return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid, 379 a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER); 380} 381 382static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) 383{ 384 int t; 385 int s_t; 386 struct net_device *dev; 387 struct Qdisc *q; 388 struct tcf_proto *tp, **chain; 389 struct tcmsg *tcm = (struct tcmsg*)NLMSG_DATA(cb->nlh); 390 unsigned long cl = 0; 391 struct Qdisc_class_ops *cops; 392 struct tcf_dump_args arg; 393 394 if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm))) 395 return skb->len; 396 if ((dev = dev_get_by_index(tcm->tcm_ifindex)) == NULL) 397 return skb->len; 398 399 if (!tcm->tcm_parent) 400 q = dev->qdisc_sleeping; 401 else 402 q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent)); 403 if (!q) 404 goto out; 405 if ((cops = q->ops->cl_ops) == NULL) 406 goto errout; 407 if (TC_H_MIN(tcm->tcm_parent)) { 408 cl = cops->get(q, tcm->tcm_parent); 409 if (cl == 0) 410 goto errout; 411 } 412 chain = cops->tcf_chain(q, cl); 413 if (chain == NULL) 414 goto errout; 415 416 s_t = cb->args[0]; 417 418 for (tp=*chain, t=0; tp; tp = tp->next, t++) { 419 if (t < s_t) continue; 420 if (TC_H_MAJ(tcm->tcm_info) && 421 TC_H_MAJ(tcm->tcm_info) != tp->prio) 422 continue; 423 if (TC_H_MIN(tcm->tcm_info) && 424 TC_H_MIN(tcm->tcm_info) != tp->protocol) 425 continue; 426 if (t > s_t) 427 memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); 428 if (cb->args[1] == 0) { 429 if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid, 430 cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER) <= 0) { 431 break; 432 } 433 cb->args[1] = 1; 434 } 435 if (tp->ops->walk == NULL) 436 continue; 437 arg.w.fn = tcf_node_dump; 438 arg.skb = skb; 439 arg.cb = cb; 440 arg.w.stop = 0; 441 arg.w.skip = cb->args[1]-1; 442 arg.w.count = 0; 443 tp->ops->walk(tp, &arg.w); 444 cb->args[1] = arg.w.count+1; 445 if (arg.w.stop) 446 break; 447 } 448 449 cb->args[0] = t; 450 451errout: 452 if (cl) 453 cops->put(q, cl); 454out: 455 dev_put(dev); 456 return skb->len; 457} 458 459void 460tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts) 461{ 462#ifdef CONFIG_NET_CLS_ACT 463 if (exts->action) { 464 tcf_action_destroy(exts->action, TCA_ACT_UNBIND); 465 exts->action = NULL; 466 } 467#elif defined CONFIG_NET_CLS_POLICE 468 if (exts->police) { 469 tcf_police_release(exts->police, TCA_ACT_UNBIND); 470 exts->police = NULL; 471 } 472#endif 473} 474 475 476int 477tcf_exts_validate(struct tcf_proto *tp, struct rtattr **tb, 478 struct rtattr *rate_tlv, struct tcf_exts *exts, 479 struct tcf_ext_map *map) 480{ 481 memset(exts, 0, sizeof(*exts)); 482 483#ifdef CONFIG_NET_CLS_ACT 484 { 485 int err; 486 struct tc_action *act; 487 488 if (map->police && tb[map->police-1]) { 489 act = tcf_action_init_1(tb[map->police-1], rate_tlv, "police", 490 TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err); 491 if (act == NULL) 492 return err; 493 494 act->type = TCA_OLD_COMPAT; 495 exts->action = act; 496 } else if (map->action && tb[map->action-1]) { 497 act = tcf_action_init(tb[map->action-1], rate_tlv, NULL, 498 TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err); 499 if (act == NULL) 500 return err; 501 502 exts->action = act; 503 } 504 } 505#elif defined CONFIG_NET_CLS_POLICE 506 if (map->police && tb[map->police-1]) { 507 struct tcf_police *p; 508 509 p = tcf_police_locate(tb[map->police-1], rate_tlv); 510 if (p == NULL) 511 return -EINVAL; 512 513 exts->police = p; 514 } else if (map->action && tb[map->action-1]) 515 return -EOPNOTSUPP; 516#else 517 if ((map->action && tb[map->action-1]) || 518 (map->police && tb[map->police-1])) 519 return -EOPNOTSUPP; 520#endif 521 522 return 0; 523} 524 525void 526tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst, 527 struct tcf_exts *src) 528{ 529#ifdef CONFIG_NET_CLS_ACT 530 if (src->action) { 531 struct tc_action *act; 532 tcf_tree_lock(tp); 533 act = xchg(&dst->action, src->action); 534 tcf_tree_unlock(tp); 535 if (act) 536 tcf_action_destroy(act, TCA_ACT_UNBIND); 537 } 538#elif defined CONFIG_NET_CLS_POLICE 539 if (src->police) { 540 struct tcf_police *p; 541 tcf_tree_lock(tp); 542 p = xchg(&dst->police, src->police); 543 tcf_tree_unlock(tp); 544 if (p) 545 tcf_police_release(p, TCA_ACT_UNBIND); 546 } 547#endif 548} 549 550int 551tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts, 552 struct tcf_ext_map *map) 553{ 554#ifdef CONFIG_NET_CLS_ACT 555 if (map->action && exts->action) { 556 /* 557 * again for backward compatible mode - we want 558 * to work with both old and new modes of entering 559 * tc data even if iproute2 was newer - jhs 560 */ 561 struct rtattr *p_rta = (struct rtattr *)skb_tail_pointer(skb); 562 563 if (exts->action->type != TCA_OLD_COMPAT) { 564 RTA_PUT(skb, map->action, 0, NULL); 565 if (tcf_action_dump(skb, exts->action, 0, 0) < 0) 566 goto rtattr_failure; 567 p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta; 568 } else if (map->police) { 569 RTA_PUT(skb, map->police, 0, NULL); 570 if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0) 571 goto rtattr_failure; 572 p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta; 573 } 574 } 575#elif defined CONFIG_NET_CLS_POLICE 576 if (map->police && exts->police) { 577 struct rtattr *p_rta = (struct rtattr *)skb_tail_pointer(skb); 578 579 RTA_PUT(skb, map->police, 0, NULL); 580 581 if (tcf_police_dump(skb, exts->police) < 0) 582 goto rtattr_failure; 583 584 p_rta->rta_len = skb_tail_pointer(skb) - (u8 *)p_rta; 585 } 586#endif 587 return 0; 588rtattr_failure: __attribute__ ((unused)) 589 return -1; 590} 591 592int 593tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts, 594 struct tcf_ext_map *map) 595{ 596#ifdef CONFIG_NET_CLS_ACT 597 if (exts->action) 598 if (tcf_action_copy_stats(skb, exts->action, 1) < 0) 599 goto rtattr_failure; 600#elif defined CONFIG_NET_CLS_POLICE 601 if (exts->police) 602 if (tcf_police_dump_stats(skb, exts->police) < 0) 603 goto rtattr_failure; 604#endif 605 return 0; 606rtattr_failure: __attribute__ ((unused)) 607 return -1; 608} 609 610static int __init tc_filter_init(void) 611{ 612 rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL); 613 rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL); 614 rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter, 615 tc_dump_tfilter); 616 617 return 0; 618} 619 620subsys_initcall(tc_filter_init); 621 622EXPORT_SYMBOL(register_tcf_proto_ops); 623EXPORT_SYMBOL(unregister_tcf_proto_ops); 624EXPORT_SYMBOL(tcf_exts_validate); 625EXPORT_SYMBOL(tcf_exts_destroy); 626EXPORT_SYMBOL(tcf_exts_change); 627EXPORT_SYMBOL(tcf_exts_dump); 628EXPORT_SYMBOL(tcf_exts_dump_stats); 629